Background: Transcranial Doppler (TCD) ultrasonography to demonstrate cerebral circulatory arrest (CCA) is a confirmatory test for brain death (BD). The primary aim of this retrospective study was to evaluate the practical utility of TCD to confirm BD when clinical diagnosis was not feasible due to confounding factors. Secondary aims were to evaluate the reasons for inability of TCD to confirm BD and to assess the outcome of patients not brain dead according to the TCD criteria.
Methods: TCD waveforms and medical records of all the patients examined to confirm suspected BD between 2001 and 2007, where clinical diagnosis was not possible, were analyzed. BD was diagnosed based on CCA criteria recommended by the Task Force Group on cerebral death of the Neurosonology Research Group of the World Federation of Neurology. Final outcome of patients and the use of other ancillary tests were noted.
Results: Ninety patients (61 males), aged 40 ± 21 (range 3-84) years underwent TCD examination for confirmation of suspected BD. TCD confirmed BD in 51 (57%) patients and was inconclusive in 38 (43%), with no flow signals on the first examination in 7 (8%) patients and the waveform patterns in 31 (35%) being inconsistent with BD. Fourteen of the 19 patients who had CCA pattern in at least one artery but did not meet all the criteria for BD were subsequently found brain dead according to SPECT/clinical criteria or suffered cardiovascular death.
Conclusion: Using the conventional criteria, TCD confirmed BD in a large proportion, of patients where clinical diagnosis could not be made. The presence of CCA pattern in one or more major cerebral artery may be prognostic of unfavorable outcome, even when BD criteria are not satisfied.